11 files changed, 12 insertions, 0 deletions
diff --git a/build_and_test_until b/build_and_test_until
index 3e353885..2220be17 100755
--- a/build_and_test_until
+++ b/build_and_test_until
@@ -1,4 +1,5 @@
 #!/bin/sh
+set -e
 
 ./clean top-level
 ./build --until $1  &&  ./mu_bin test
diff --git a/clean b/clean
index e9b2eeb9..3b629daa 100755
--- a/clean
+++ b/clean
@@ -1,4 +1,5 @@
 #!/bin/sh
+set -e
 
 set -v
 rm -rf mu.cc core.mu mu_bin* *_list .build
diff --git a/git_log_filtered b/git_log_filtered
index b17cd3bf..7ab6d43e 100755
--- a/git_log_filtered
+++ b/git_log_filtered
@@ -4,5 +4,6 @@
 # I usually run this through an alias local to this repo:
 #   $ git config alias.ll '!./git_log_filtered'
 #   $ git ll --stat
+set -e
 
 git log $* -- . ":(exclude)html"
diff --git a/linkify/build b/linkify/build
index 54c3f459..3c96ad00 100755
--- a/linkify/build
+++ b/linkify/build
@@ -1,3 +1,4 @@
 #!/bin/sh
+set -e
 
 c++ -g linkify.cc -o linkify
diff --git a/linkify/clean b/linkify/clean
index 7838b78a..3feef907 100755
--- a/linkify/clean
+++ b/linkify/clean
@@ -1,2 +1,4 @@
 #!/bin/sh
+set -e
+
 rm -rf linkify *.dSYM
diff --git a/mu b/mu
index 964816f3..7e3d6be6 100755
--- a/mu
+++ b/mu
@@ -1,5 +1,6 @@
 #!/bin/sh
 # Run interpreter, first compiling if necessary.
+set -e
 
 ./build  &&  ./mu_bin "$@"
 
diff --git a/snapshot_lesson b/snapshot_lesson
index 2a943c37..cd4723c1 100755
--- a/snapshot_lesson
+++ b/snapshot_lesson
@@ -1,6 +1,7 @@
 #!/bin/sh
 # Hacky little helper called from edit/ and sandbox/ apps to save a snapshot
 # of lesson/ using git.
+set -e
 
 test -d lesson/.git || exit 0  # give up if it's not a git repo
 
diff --git a/subx/build_and_test_until b/subx/build_and_test_until
index 25daac2d..874d1254 100755
--- a/subx/build_and_test_until
+++ b/subx/build_and_test_until
@@ -1,4 +1,5 @@
 #!/bin/sh
+set -e
 
 ./clean top-level  # ignore subsidiary tools like tangle and cleave
 ./build --until $1  &&  ./subx_bin test
diff --git a/subx/clean b/subx/clean
index 5243f243..6ee90a9c 100755
--- a/subx/clean
+++ b/subx/clean
@@ -1,4 +1,5 @@
 #!/bin/sh
+set -e
 
 set -v
 rm -rf subx.cc subx_bin* *_list
diff --git a/subx/subx b/subx/subx
index 5d7a237c..257e2f13 100755
--- a/subx/subx
+++ b/subx/subx
@@ -1,4 +1,5 @@
 #!/bin/sh
 # Run SubX VM, first compiling if necessary.
+set -e
 
 ./build  &&  ./subx_bin "$@"
diff --git a/test_layers b/test_layers
index 69d9818e..e004b796 100755
--- a/test_layers
+++ b/test_layers
@@ -13,6 +13,7 @@
 #     test_layers x y
 #   Test all layers for a specific app:
 #     test_layers app
+set -e
 
 if [[ $1 == one-off ]]
 then